PURPOSE The purpose of this study was to investigate the effects of ankle muscle contraction method on strength, flexibility and balance of ankle joint in high school football player. METHODS Thirty-six high school soccer male players participated in this study. There were three groups (1) concentric contraction exercise (CON, n = 12), (2) eccentric contraction exercise (ECC, n = 12) and (3) CON + ECC (n = 12). Exercise program consist of plantar flexion, dorsi flexion, and inversion, eversion and these exercise was performed 10 repetition, 2set (CON+ECC=1set), 30°/sec, 60°/sec, 90°/sec, 120°/sec in each group. All subjects performed same volume of exercise condition on a isokinetic exercise. RESULTS First, the muscle strength of the ankle joint was significantly higher after isokinetic exercise program in plantar flexion (p<.05), dorsi flexion (p<.01), inversion (p<,05) and eversion (p<.01). Second, the flexibility of the ankle joint was significantly higher than in plantar flexion (p<.01), dorsi flexion (p<.05), inversion (p<,05) and eversion (p<.01). Third, blance of the ankle joint was higher (p<.05) in the anterior and anterolateral joints compared with the group that performed only the concentricl contraction and the eccentric contraction (P<.05) compared to before the isokinetic exercise program. In the lateral direction, there was a significant difference between groups (p<.01) and between measurement periods (p<.05). In the posterolateral direction, the combi-nation of the concentric contraction and eccentric contractions was higher than the group with only the concen-tric and eccentric contraction (P <.01). In the posterior direction, there was a significant difference between the groups (p<.01) and the measurement period (p<.05). Significant differences were noted between posteromedial and medial direction (p<.01). CONCLUSIONSThese suggest that the combined of concentric and eccentric contraction exercise of ankle joint can improve to greater balance compared with only performing concentric and eccentric contraction exercise.
Conflicts of Interest